The unique identifier for the cache policy that you are deleting. To get the identifier, you can use ListCachePolicies.
ListCachePolicies
The version of the cache policy that you are deleting. The version is the cache policy's ETag value, which you can get using ListCachePolicies, GetCachePolicy, or GetCachePolicyConfig.
ETag
GetCachePolicy
GetCachePolicyConfig